APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Next Issue

6 Jan 1997

Volume 70, Issue 1, pp. 1-140

Page 2 of 2 Pages Previous Page | Jump to Page

Anisotropy and growth-sequence dependence of atomic-scale interface structure in InAs/Ga1−xInxSb superlattices

A. Y. Lew, S. L. Zuo, E. T. Yu, and R. H. Miles

Appl. Phys. Lett. 70, 75 (1997); http://dx.doi.org/10.1063/1.119311 (3 pages) | Cited 19 times

Full Text: | Download PDF

Show Abstract
We have used cross-sectional scanning tunneling microscopy to study the atomic-scale interface structure of InAs/Ga1−xInxSb superlattices grown by molecular beam epitaxy. Detailed, quantitative analysis of interface profiles obtained from constant-current images of both (110) and (110) cross-sectional planes of the superlattice indicate that interfaces in the (110) plane exhibit a higher degree of interface roughness than those in the (110) plane, and that the Ga1−xInxSb-on-InAs interfaces are rougher than the InAs-on-Ga1−xInxSb interfaces. The roughness data are consistent with anisotropy in interface structure arising from anisotropic island formation during growth, and in addition a growth-sequence-dependent interface asymmetry resulting from differences in interfacial bond structure between the superlattice layers. © 1997 American Institute of Physics.
Show PACS
68.35.Ct Interface structure and roughness
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)
68.37.Ps Atomic force microscopy (AFM)
68.37.Rt Magnetic force microscopy (MFM)
68.37.Uv Near-field scanning microscopy and spectroscopy

Nonequilibrium hydrogen temperatures under diamond chemical vapor deposition conditions

Robert S. Sinkovits

Appl. Phys. Lett. 70, 78 (1997); http://dx.doi.org/10.1063/1.119312 (3 pages)

Full Text: | Download PDF

Show Abstract
Direct simulation Monte Carlo calculations indicate that significant differences can exist between the translational, rotational, and vibrational temperatures of molecular hydrogen under diffusion-dominated diamond chemical vapor deposition conditions. For hydrogen confined in a 1 cm gap between an activating source and a diamond substrate, the largest discrepancies between the translational and rotational temperatures of H2 occur at a pressure of approximately 2 Torr, but measurable differences persist for pressures exceeding 20 Torr. The observed trends are due to the inefficiency of intermolecular collisions at exciting the internal modes of H2. © 1997 American Institute of Physics.
Show PACS
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
33.20.Vq Vibration-rotation analysis

Efficient doping of nitrogen with high activation ratio into ZnSe using a high-power plasma source

K. Kimura, S. Miwa, T. Yasuda, L. H. Kuo, C. G. Jin, K. Tanaka, and T. Yao

Appl. Phys. Lett. 70, 81 (1997); http://dx.doi.org/10.1063/1.119314 (3 pages) | Cited 6 times

Full Text: | Download PDF

Show Abstract
We have developed a high-power (5 kW) rf plasma source for nitrogen doping in ZnSe molecular beam epitaxy. Optical emission spectroscopy shows dominant atomiclike emissions around 800 nm due to excited neutral nitrogen atoms in the high power region and their intensities rapidly increase with increasing the rf power from 1 to 3 kW. The high net acceptor concentration (NA–ND) of 1.2×1018 cm−3 was achieved at the growth temperature of 220 °C and the activation ratio [(NA–ND)/N] as high as 60%, which is the highest value so far obtained for NA–ND ∼ 1018 cm−3. Consequently, the PL spectrum showed well-resolved deep donor-acceptor pair emissions even with high NA–ND. © 1997 American Institute of Physics. 
Show PACS
61.72.uj III-V and II-VI semiconductors
52.77.Bn Etching and cleaning
52.77.Dq Plasma-based ion implantation and deposition
81.05.Dz II-VI semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy

Observation of trap states in Er-doped InP by photoreflectance

Jiti Nukeaw, Jun Yanagisawa, Naoteru Matsubara, Yasufumi Fujiwara, and Yoshikazu Takeda

Appl. Phys. Lett. 70, 84 (1997); http://dx.doi.org/10.1063/1.119315 (3 pages) | Cited 3 times

Full Text: | Download PDF

Show Abstract
We have investigated room-temperature photoreflectance (PR) spectra in Er-doped InP grown by low-pressure organometallic vapor phase epitaxy. A new feature is clearly observed at 1.31 eV, accompanied with a feature due to the bandgap transition at 1.35 eV. The new feature is attributed to a transition involving an Er trap. The transition energy is independent of both doping processing techniques and concentrations of Er in the layers. The PR spectral width of the trap transition energy described by the broadening parameter, increases linearly with the logarithm of Er concentrations. © 1997 American Institute of Physics.
Show PACS
71.55.Eq III-V semiconductors
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
78.40.Fy Semiconductors

Pure strain effect on reducing the chirp parameter in InGaAsP/InP quantum well electroabsorption modulators

Takayuki Yamanaka, Koichi Wakita, and Kiyoyuki Yokoyama

Appl. Phys. Lett. 70, 87 (1997); http://dx.doi.org/10.1063/1.119316 (3 pages) | Cited 4 times

Full Text: | Download PDF

Show Abstract
The pure strain dependence of the chirp parameter (linewidth enhancement factor) of electroabsorption in the 1.55 μm window for strain ranging from compression to tension is studied theoretically in InGaAsP strained quantum well (QW) structures. The small-signal chirp parameter for TE polarization is evaluated from calculated electroabsorption (EA) spectra based on k⋅p theory and their Kramers–Krönig transformed refractive index changes. It is found that both compressive and tensile strain in the well layer reduce the chirp parameter. In a tensile-strained QW, almost continuously negative values irrespective of applied electric fields occur at an optimized amount of strain. The compressive-strained QW lowers the chirp parameter to nearly zero or negative values, the amount of the reduction being proportional to strain amount. © 1997 American Institute of Physics.
Show PACS
85.60.Bt Optoelectronic device characterization, design, and modeling
78.20.Bh Theory, models, and numerical simulation
78.20.Jq Electro-optical effects
42.79.Hp Optical processors, correlators, and modulators

Effect of illumination on the subband electronic structure of Si δ-doped GaAs

G. Li and C. Jagadish

Appl. Phys. Lett. 70, 90 (1997); http://dx.doi.org/10.1063/1.119317 (3 pages) | Cited 9 times

Full Text: | Download PDF

Show Abstract
The subband electronic structure of Si δ-doped GaAs grown by metal organic vapor phase epitaxy was investigated using magnetotransport measurements. The work focused on the effect of illumination. We found that illumination leads to a slight increase of the quasi-two dimensional electron gas density in the well. This increase does not depend on the illumination intensity. The illumination-generated electron density weakly increases with an increase in the Si δ-doping concentration. We also experimentally confirmed that illumination only slightly alters the electron densities of the occupied subbands and the illumination-generated electrons populate one previously empty subband. Only a fraction of the illumination-generated electrons persist but the newly occupied subband under illumination remains populated in the dark after removal of the illumination. The experimental results suggest that the DX centers are unlikely to be populated in our Si δ-doped GaAs regardless of the doping concentration. The weak and partially persistent photoconductivity effect observed in Si δ-doped GaAs may arise from ionization of other Si localized states.© 1997 American Institute of Physics.
Show PACS
71.20.Nr Semiconductor compounds
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
73.61.Ey III-V semiconductors

A 40-nm-pitch double-slit experiment of hot electrons in a semiconductor under a magnetic field

Hiroo Hongo, Yasuyuki Miyamoto, Kazuhito Furuya, and Michihiko Suhara

Appl. Phys. Lett. 70, 93 (1997); http://dx.doi.org/10.1063/1.119318 (3 pages) | Cited 8 times

Full Text: | Download PDF

Show Abstract
We report a double-slit experiment of hot electrons in a semiconductor under a magnetic field. The pitch of the double slit buried in the semiconductor is 40 nm and the electron energy is of the order of 100 meV. By applying a magnetic field, the change in current that passes through the slits is observed at the segmented collector. The measured current shows a clear minimum around B=0 T, with this behavior agreeing with a theoretical calculation based on double-slit interference. Quantitative estimation is consistent with this order of current variation. We think that these results show evidence of the observation of hot electron interference by a double slit in a semiconductor. © 1997 American Institute of Physics.
Show PACS
73.23.Ad Ballistic transport
85.35.Ds Quantum interference devices

1.3 μm strain-compensated InAsP/InGaP electroabsorption modulator structure grown by atmospheric pressure metal–organic vapor epitaxy

A. Ougazzaden, F. Devaux, E. V. K. Rao, L. Silvestre, and G. Patriarche

Appl. Phys. Lett. 70, 96 (1997); http://dx.doi.org/10.1063/1.119319 (3 pages) | Cited 10 times

Full Text: | Download PDF

Show Abstract
High quality 15-period strain-compensated InAsP/InGaP electroabsorption (EA) modulator structures have been grown by atmospheric pressure metal–organic vapor epitaxy. The incorporation of large compressive strain (∼1.7%) in the InAsP wells and tensile strain (∼−1.8%) in the InGaP barriers necessitated the growth of a few InP monolayers between the wells and barriers. The high structural quality of such samples has been demonstrated by (cross-sectional transmission electron microscopy analysis to be free of misfit dislocations and thickness undulations. The detection of a sharp and abrupt room-temperature exciton peak both in the photoconductivity and photoluminescence measurements further confirmed their excellent optical quality. 100 μm cavity length EA modulators fabricated in these structures exhibited excellent performances namely, an extinction ratio higher than 20 dB for 2.5 V drive voltage, a 3 dB bandwidth over 20 GHz, and low coupling losses to fiber (less than 2.5 dB per facet). © 1997 American Institute of Physics.
Show PACS
42.79.Hp Optical processors, correlators, and modulators
78.20.Jq Electro-optical effects
81.15.Kk Vapor phase epitaxy; growth from vapor phase
85.60.Bt Optoelectronic device characterization, design, and modeling

Low resistance Ohmic contact scheme (∼μΩ cm2) to p-InP

Moon-Ho Park, L. C. Wang, J. Y. Cheng, and C. J. Palmstrøm

Appl. Phys. Lett. 70, 99 (1997); http://dx.doi.org/10.1063/1.119320 (3 pages) | Cited 12 times

Full Text: | Download PDF

Show Abstract
A low resistance Pd/Sb/Zn/Pd Ohmic contact based on the solid phase regrowth principle has been investigated to p-InP. Contact resistivity as low as ∼ 2×10−6 Ω cm2 has been obtained for samples annealed at 500 °C for 1 min. The Ohmic behavior can be rationalized by the formation of a heavily doped surface layer or a heterojunction. The InSb phase responsible for the observed low resistivity is identified using the x-ray diffraction technique. © 1997 American Institute of Physics.
Show PACS
73.40.Cg Contact resistance, contact potential
72.80.Ey III-V and II-VI semiconductors
73.40.Ns Metal-nonmetal contacts
68.55.Nq Composition and phase identification

Effect of indirect Γ-L and Γ-X transfer on the carrier dynamics of InGaP/InAlP multiple quantum wells

C. S. Menoni, O. Buccafusca, M. C. Marconi, D. Patel, J. J. Rocca, G. Y. Robinson, and S. M. Goodnick

Appl. Phys. Lett. 70, 102 (1997); http://dx.doi.org/10.1063/1.119275 (3 pages) | Cited 3 times

Full Text: | Download PDF

Show Abstract
Indirect Γ-L scattering within the well, and real space carrier transfer to the barrier X1c states are shown to significantly affect the carrier dynamics in In0.48Ga0.52P/In0.5Al0.5P multiple quantum wells. When carriers transfer to the indirect states occurs, the carrier dynamics is modified by the slow return of the carriers from the low mobility states to the well. As a result, the absorption recovery time increases by almost an order of magnitude. Carrier transfer to the indirect states also increases the carrier lifetime to values characteristic of indirect recombination. © 1997 American Institute of Physics.
Show PACS
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths

Resonant tunneling of electrons via 20 nm scale InAs quantum dot and magnetotunneling spectroscopy of its electronic states

M. Narihiro, G. Yusa, Y. Nakamura, T. Noda, and H. Sakaki

Appl. Phys. Lett. 70, 105 (1997); http://dx.doi.org/10.1063/1.119276 (3 pages) | Cited 67 times

Full Text: | Download PDF

Show Abstract
The resonant tunneling of electrons through a 20 nm scale InAs quantum dot bound by a pair of very thin AlAs barriers is studied. A well-resolved composite peak resulting from the ground 1s states was observed at 4.2 K in current–voltage characteristics. By investigating the effects of inplane magnetic fields, the shape of the wave function and the spatial extent of the first two electronic states are clarified. © 1997 American Institute of Physics.
Show PACS
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
73.40.Gk Tunneling
73.61.Ey III-V semiconductors

Ohmic contacts to n-GaN using PtIn2

D. B. Ingerly, Y. A. Chang, N. R. Perkins, and T. F. Kuech

Appl. Phys. Lett. 70, 108 (1997); http://dx.doi.org/10.1063/1.119277 (3 pages) | Cited 16 times

Full Text: | Download PDF

Show Abstract
A new metallization scheme has been developed to form Ohmic contacts to n-GaN. Contacts were fabricated by sputtering the intermetallic compound, PtIn2 on metal–organic vapor phase epitaxy grown n-GaN (n ∼ 5×1017 cm−3) with some of the contacts subjected to rapid thermal annealing. Contacts in the as-deposited state exhibited nearly Ohmic behavior with a specific contact resistance of 1.2×10−2 Ω cm2. Contacts subjected to rapid thermal annealing at 800 °C for 1 min exhibited linear current–voltage characteristics and had specific contact resistances less than 1×10−3 Ω cm2. Auger depth profiling and glancing angle x-ray diffraction were used to examine the interfacial reactions of the PtIn2/n-GaN contacts. Consistent with estimated phase diagram information, the results from Auger depth profiling and glancing angle x-ray diffraction indicated the formation of (InxGa1−x)N at the contact interface, which could be responsible for the Ohmic behavior of PtIn2 contacts. © 1997 American Institute of Physics.
Show PACS
73.40.Cg Contact resistance, contact potential
73.40.Ns Metal-nonmetal contacts
85.40.Ls Metallization, contacts, interconnects; device isolation
61.05.cm X-ray reflectometry (surfaces, interfaces, films)

Confinement potential and surface state density in deep-mesa etched quantum wires

S. P. Riege, T. Kurth, F. Runkel, D. Heitmann, and K. Eberl

Appl. Phys. Lett. 70, 111 (1997); http://dx.doi.org/10.1063/1.119278 (3 pages) | Cited 11 times

Full Text: | Download PDF

Show Abstract
We present an electrostatic model to determine the surface charge density and confinement potential in etched AlGaAs/GaAs quantum wires. In far-infrared transmission experiments we have determined the resonance frequencies of the dynamic eigenmodes of the quantum wire, which gives an independent determination of the confinement potential. We find good agreement with the modeled potential, which shows that this model gives a very good description of the electronic system. © 1997 American Institute of Physics.
Show PACS
73.20.At Surface states, band structure, electron density of states
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
78.30.Fs III-V and II-VI semiconductors

NbN/AlN/NbN tunnel junctions with high current density up to 54 kA/cm2

Zhen Wang, Akira Kawakami, and Yoshinori Uzawa

Appl. Phys. Lett. 70, 114 (1997); http://dx.doi.org/10.1063/1.119279 (3 pages) | Cited 19 times

Full Text: | Download PDF

Show Abstract
We report on progress in the development of high current density NbN/AlN/NbN tunnel junctions for applications as submillimeter wave superconductor-insulator-superconductor mixers. A very high current density up to 54 kA/cm2, roughly an order of magnitude larger than any reported results for all-NbN tunnel junctions, was achieved in the junctions with about 1 nm thick AlN barriers. The magnetic field and temperature dependence of critical supercurrents were measured to investigate the Josephson tunneling behavior of critical supercurrents in the high-Jc junctions. The junctions showed high-quality junction characteristics with a large gap voltage of 5 mV and sharp quasiparticle current rise (ΔVg = 0.1 mV). The Rsg/RN ratio was about 5 with a Vm value of 14 mV measured at 4.2 K. © 1997 American Institute of Physics.
Show PACS
74.45.+c Proximity effects; Andreev reflection; SN and SNS junctions
74.50.+r Tunneling phenomena; Josephson effects
74.78.-w Superconducting films and low-dimensional structures
74.25.N- Response to electromagnetic fields

High trapped fields in bulk YBa2Cu3O7−δ samples at temperatures around 50 K

G. Fuchs, G. Krabbes, P. Schätzle, S. Gruβ, P. Stoye, T. Staiger, K.-H. Müller, J. Fink, and L. Schultz

Appl. Phys. Lett. 70, 117 (1997); http://dx.doi.org/10.1063/1.119280 (3 pages) | Cited 27 times

Full Text: | Download PDF

Show Abstract
Bulk melt textured YBa2Cu3O7−δ samples with single grains of about 24 mm diameter were obtained by use of SmBa2Cu3O7−x seed crystals. The maximum trapped field B0 in the gap between two samples was investigated as function of temperature. B0 increased from 1 T at 77 K to 8.5 T at 51.5 K, which is the highest trapped field achieved in nonirradiated samples. At low temperatures, cracking of the samples was observed under magnetic pressure. In this temperature range, the trapped field is limited by the mechanical strength of the samples, for which a value of 25 MPa was estimated. © 1997 American Institute of Physics.
Show PACS
74.72.-h Cuprate superconductors
74.81.Bd Granular, melt-textured, amorphous, and composite superconductors
74.25.Ld Mechanical and acoustical properties, elasticity, and ultrasonic attenuation

Scaling behavior of 1/f noise in high-temperature superconductor Josephson junctions

A. Marx and R. Gross

Appl. Phys. Lett. 70, 120 (1997); http://dx.doi.org/10.1063/1.119281 (3 pages) | Cited 24 times

Full Text: | Download PDF

Show Abstract
Extensive studies of the low frequency 1/f noise in high-temperature superconducting (HTS) Josephson junctions of various types and materials have been performed for a wide range of operating parameters. The origin of the measured voltage fluctuations can be traced back to the trapping and release of charge carriers in trapping centers in an insulating barrier, giving rise to correlated fluctuations of the junction critical current Ic and normal-state resistance Rn. We observed a linear dependence of the normalized critical current and resistance fluctuations on Rn, which suggests a constant density of trapping centers for the HTS Josephson junctions. The scaling of the normalized fluctuations is in good agreement with the previously found scaling relation IcRn∝1/Rn and supports a junction model assuming a leaky tunnel barrier. © 1997 American Institute of Physics.
Show PACS
74.40.-n Fluctuation phenomena
74.50.+r Tunneling phenomena; Josephson effects
74.78.-w Superconducting films and low-dimensional structures

Fast and sensitive suspended YBaCuO microbolometers using silicon separated by implanted oxygen substrates

Laurence Méchin, Jean-Claude Villégier, and Daniel Bloyet

Appl. Phys. Lett. 70, 123 (1997); http://dx.doi.org/10.1063/1.119282 (3 pages) | Cited 6 times

Full Text: | Download PDF

Show Abstract
A process to fabricate epitaxial YBaCuO suspended microbolometers using silicon separated by implanted oxygen (SIMOX) substrates is reported. Unlike the other micromachining techniques, no process step is needed after film deposition and the YBaCuO air-bridge retains excellent superconducting qualities. The support membrane is constituted of a 80-nm-thick CeO2/YSZ buffer layer on a 150-nm-thick silicon layer. The critical temperature Tc(R = 0) is 88 K and the transition width is 2.5 K. Current-voltage characteristics directly measured on a 10-μm-wide, 100-μm-long suspended bridge show a critical current density of 7.5×105 A/cm2 at 80 K. The thermal conductance G of this bridge is 2×10−5 W/K. An optical noise equivalent power (NEP) of 6.1×10−12 W/math at 1 kHz is deduced from optical sensitivity and noise measurements. The time constant is 6 μs, which is the lowest value reported on such suspended structures. Comparison with a similar suspended bridge fabricated without a silicon layer shows that the sensitivity–bandwidth product of the SIMOX bridge is improved by one order of magnitude, thus demonstrating the feasibility of sensitive and fast YBaCuO bolometers. © 1997 American Institute of Physics.
Show PACS
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
74.78.-w Superconducting films and low-dimensional structures
85.25.Pb Superconducting infrared, submillimeter and millimeter wave detectors

Ti and Ca substitution in SrRuO3 thin films by sequential deposition process

L. Miéville, T. H. Geballe, L. Antognazza, and K. Char

Appl. Phys. Lett. 70, 126 (1997); http://dx.doi.org/10.1063/1.119283 (3 pages) | Cited 26 times

Full Text: | Download PDF

Show Abstract
We report on the growth and properties of (Sr1−xCax)RuO3 and Sr (Ru1−xTix)O3 thin films obtained by sequential deposition of submonolayers from end members of each compound. Magnetization measurements as well as transport properties exhibit a very different behavior for each type of substitution. A simple model, which assumes a random distribution of the substituted sites, allows us to account quantitatively for the reduction of the magnetization with increased doping and further confirms the homogeneity of our samples. A strong distortion due to the presence of the Ti on the Ru site could explain the different behavior observed between both types of doping. © 1997 American Institute of Physics.
Show PACS
75.70.Ak Magnetic properties of monolayers and thin films
75.50.Dd Nonmetallic ferromagnetic materials
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
81.15.Fg Pulsed laser ablation deposition

Structure and magnetism of the Fe/GaAs interface

A. Filipe, A. Schuhl, and P. Galtier

Appl. Phys. Lett. 70, 129 (1997); http://dx.doi.org/10.1063/1.119284 (3 pages) | Cited 92 times

Full Text: | Download PDF

Show Abstract
We study the magnetic properties of Fe thin films epitaxially grown on GaAs (001) for a large range of substrate temperature. Magnetization deficiency has been observed and studied. Its dependence on both thickness and temperature clearly show the existence of a nearly half-magnetized phase at the interface, covered by “as-bulk” Fe. Furthermore, reflection high-energy electron diffraction studies show a transition between two bcc structures with different crystalline parameters. Transmission electron microscopy confirms the formation of this interfacial phase, for which the compound Fe3Ga2−xAsx seems to be the best candidate. © 1997 American Institute of Physics.
Show PACS
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
68.35.Ct Interface structure and roughness
61.05.jh Low-energy electron diffraction (LEED) and reflection high-energy electron diffraction (RHEED)

The effect of the microstructure on the magnetic interactions in CoFe–AgCu granular films: From demagnetizing to magnetizing interactions

X. Batlle, V. Franco, A. Labarta, M. L. Watson, and K. O’Grady

Appl. Phys. Lett. 70, 132 (1997); http://dx.doi.org/10.1063/1.119285 (3 pages) | Cited 15 times

Full Text: | Download PDF

Show Abstract
The sign and strength of the dominant magnetic interactions in Co34Fe8Ag54Cu4 granular films were modified by changing the microstructure through annealing. Magnetic force micrographs showed that in the as-cast sample the magnetic moments of neighboring grains tended to be arranged parallel along a direction out of the film plane, forming elongated magnetic clusters that were themselves aligned antiparallel, with dominant demagnetizing interactions. This is a direct evidence that an uncompensated antiferromagneticlike microstructure is stabilized below the volume percolation threshold. However, in the sample annealed at 750 °C the particle growth led to large in-plane ferromagneticlike clusters with dominant magnetizing interactions. Thus, in this letter we present direct correlation of interactions effects with magnetic measurements and show that ΔM plots correlate with changes in the magnetic microstructure in these systems. © 1997 American Institute of Physics.
Show PACS
75.70.Ak Magnetic properties of monolayers and thin films
75.50.Bb Fe and its alloys
81.40.Rs Electrical and magnetic properties related to treatment conditions

High resolution imaging of thin-film recording heads by superparamagnetic magnetic force microscopy tips

S. H. Liou, S. S. Malhotra, John Moreland, and P. F. Hopkins

Appl. Phys. Lett. 70, 135 (1997); http://dx.doi.org/10.1063/1.119286 (3 pages) | Cited 8 times

Full Text: | Download PDF

Show Abstract
We have used superparamagnetic magnetic force microscopy (MFM) tips to obtain high spatial resolution MFM images of recording heads. Profiles of the magnetic field gradient above a thin-film recording head under 3 mA bias current to the head and various tip-head distance conditions are presented. At a low tip-head distance, the gap width, gap location, and gap-field structure can be well resolved in these MFM images. Superparamagnetic tips show promise for the magnetic imaging of recording heads with gap widths below 200 nm. © 1997 American Institute of Physics.
Show PACS
07.79.Pk Magnetic force microscopes
85.70.Kh Magnetic thin film devices: magnetic heads (magnetoresistive, inductive, etc.); domain-motion devices, etc.
75.50.Ss Magnetic recording materials

Fatigue resistance in lead zirconate titanate thin ferroelectric films: Effect of cerium doping and frequency dependence

S. B. Majumder, Y. N. Mohapatra, and D. C. Agrawal

Appl. Phys. Lett. 70, 138 (1997); http://dx.doi.org/10.1063/1.119287 (3 pages) | Cited 39 times

Full Text: | Download PDF

Show Abstract
We demonstrate improvement in fatigue resistance and other ferroelectric properties through cerium doping in sol–gel derived lead zirconate titanate thin films. We have studied frequency dependence of fatigue behavior and show that the loss of polarization due to fatigue follows a universal scaling behavior with N/f2, where N is the number of switching cycles and f the frequency. The origin of the scaling is attributed to the drift of oxygen vacancies, which is the rate limiting process in the growth of the interface layer responsible for fatigue. Empirical fits for both undoped and cerium-doped samples show that switchable polarization follows stretched exponential decay with time or N/f. Cerium doping is shown to improve fatigue resistance by impeding the motion of oxygen vacancies. © 1997 American Institute of Physics.
Show PACS
77.80.Fm Switching phenomena
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
Page 2 of 2 Pages Previous Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close